热等静压温度对第三代单晶高温合金DD10组织的影响

Effect of Hot Isostatic Pressing Temperature on the Microstructure of a Third Generation Single Crystal Superalloy DD10

采用OM,SEM以及EPMA等手段对比研究了不同热等静压温度对第三代单晶高温合金DD10组织的影响。结果表明:在150MPa压力条件下,1290℃热等静压即可使第三代单晶高温合金DD10中的显微疏松完全闭合;随热等静压温度的升高,共晶体积分数逐渐减少,热等静压温度达到1310℃及以上温度,共晶完全溶于基体。在1340℃/150MPa热等静压后,合金中出现局部初熔。热等静压后DD10单晶高温合金的γ′相立方度提高,不同热等静压温度对γ′相的形貌影响基本相同。热等静压降低了DD10单晶高温合金的枝晶偏析,并且热等静压温度越高,枝晶偏析改善越明显。

The effects of different hot isostatic pressing temperatures on the microstructures of the third generation single crystal superalloy DD10 were investigated by using optical microscope （OM）, scanning electron microscope （SEM） and electron microprobe analyzer （EPMA）. The results show that the hot isostatic pressing temperature 1290℃ was enough for the mieroporosity of DD10 to be eliminated completely at 150MPa; the volume fraction of euteetic was decreased markedly with the increase of the hot isostatic pressing temperature. The euteetie disappeared with hot isostatic pressing of 1310℃ or above, and there were internal incipient melting after hot isostatic pressing at 1340℃/ 150MPa. Meanwhile, the hot isostatic pressing process with different temperatures also resulted in more uniform morphology of γ precipitates to the same extent. The dendritic segregation was homogenized gradually because of increasing of the hot isostatic pressing temperature.